A coalition of more than 40 leading children's organisations and experts has written to government urging it to reject several proposals from a major review of the fostering system, because they would "greatly weaken" legal protections for vulnerable children.

The government commissioned fostering stocktake, published last month, makes a total of 36 recommendations, including the establishment of a national register of foster carers and improvements to commissioning.

In a letterto children's minister Nadhim Zahawi, the coalition said the five highlighted recommendations should be rejected as they would weaken the legal protection of looked-after children.

Regarding the recommendation to axe IROs, the coalition said the role is vital in supporting young people and should be retained. In addition, they are concerned that this recommendation is not backed by evidence and goes beyond the review's remit.

"This recommendation could have a profound impact on the rights and welfare of children, including those who are remanded to custody, yet there is a dearth of evidence for it within the stocktake report," states the coalition's letter to Zahawi.

"The fostering stocktake was not designed to review the role of IROs in safeguarding and promoting the rights and welfare of children in foster care, let alone across the care system.

"There was no call for evidence about the IRO role, and the authors of the stocktake report have no professional background or expertise in this policy area."

"The authors' conclusion that ‘despite the commendable commitment of some individuals, we saw little to recommend the IRO role' displays a level of confidence out of synch with the report's rudimentary analysis.

The coalition also wants Zahawi to reject a recommendation that councils should not presume that brothers and sisters in care should live together. Such a move would not be compatible with the European Convention on Human Rights, the coalition said.

"This is a radical proposal that flies in the face of established childcare practice and law. It implicitly dismisses decades of testimony from children in care and care leavers," states their letter.

Other recommendations the coalition wants to see rejected are for a single social worker to supervise carers and support children in long-term foster placements. The coalition backs retaining the current system, where children have their own social worker.

"Children having their own social worker is a fundamental safeguard and a lynch-pin of the care system," states the letter.

"When it works well, it gives children the opportunity to develop a positive and trusting relationship through which they can safely explore their history and identity, share their experiences and raise any concerns."

The stocktake's recommendation to remove day-to-day authority from parents whose children are being voluntarily taken into care is also rejected by the coalition.

They also urge Zahawi to ignore the stocktake's call for a review of the effectiveness and value for money of fostering panels.

"The 'case' for a review of fostering panels is made in a very short paragraph with a single quote from an unnamed 'distinguished commentator'," the letter states.

"There is no discussion of the evolution or legal basis of fostering panels."

This is the second major campaign by the coalition, which last year successfully lobbied against the inclusion of controversial plans to allow councils to apply for exemptions from social care legislation.